Figure 265. Eight of the nine Dusky Warblers found in California have been fall vagrants along the coast (see also Appendix H), but this one was present on 4 and 5 October 1997 inland near Cantil, Kern County, where it was photographed on the second day (1997-143; John C. Wilson).

 

Figure 375. California’s fourth Dusky Warbler, as it appeared to the finder at Goleta, Santa Barbara County, 22 October 1993 (1993-160; Shawneen E. Finnegan).

 

 

 

 

 

 

DUSKY WARBLER Phylloscopus fuscatus (Blyth, 1842)

Accepted: 9 (100%)	Treated in Appendix H: yes
Not accepted: 0	CBRC review: all records
Not submitted/reviewed: 1	Color image: see Figures

This secretive bird breeds from eastern Siberia south and west to Mongolia and the eastern Himalayas, and winters from India east through Southeast Asia and southern China. The species is a rare fall vagrant to the Western Palearctic, where the rate of detection peaks during late October and early November (Vinicombe and Cottridge 1996). Migrants occur casually among the islands of western Alaska, having been recorded four times in spring (31 May–13 June, including one collected in the central Bering Sea) and roughly 12 times in fall (21 August–23 September) (Gibson and Kessel 1992, Lehman 2005). A somewhat later fall migrant was present 26–27 September 1997 on Middleton Island in south-central Alaska (FN 52:110). Two Alaska specimens are P. p. fuscatus, the more expected of the two subspecies (Gibson and Kessel 1997). Two fall vagrants have been documented in Baja California: a 15 October 1991 sight record from the Maneadero Plain and a 20–23 October 1995 photographic record from Cataviña.

California’s first Dusky Warbler was a first-fall female of the nominate subspecies collected on 27 September 1980 on Southeast Farallon Island (Pyle et al. 1983). Eight more have since been found, all between 27 September and 3 November; see also Appendix H. The four birds recorded during fall 1997, including one inland near Cantil in Kern County (Figure 265), represents a single-season concentration of records that was only later matched in Alaska, when four were recorded at Gambell in fall 2002 (Lehman 2005). An Old World influx of Dusky Warblers during October and November 1987 generated records of 13 birds in the British Isles, ten in Denmark, seven in Sweden, and scattered records elsewhere in Europe (Lewington et al. 1991).

In addition to the Arctic Warbler, other Asian Phylloscopus warblers could reach California (see Erickson and Terrill 1996). Field identification of the treacherous Dusky/Radde’s (P. schwarzi)/Yellow-streaked (P. armandii) Warbler complex has been covered in works by Johns and Wallace (1972), Madge (1987, 1990), Round (1988), Lewington et al. (1991), Parmenter and Byers (1991), Bradshaw (1994), Leader (1995), and Baker (1997).